Just another look.  The reason i am on these currently is that we may be doing his ourselves, locally.  In setting it up, one realizes the real cost is labor.  Technically, it is quite simple, pouring an underlayment of cement in order to manitin a perfect grade, and selecting pretty much perfectly-matched pebbles.  This is not so hard.  Many rock and aggregate dealers have sieves which perform this, shaking out similarly-sized rocks and isolating them. Thus they become them avaiable commerically. The real work is in spreading a layer of cement, then placing the darn pebbles.  A good washing afterwards is vital, of course, like removing grout from tiles.  We will, as these guys did, add a sealant over the top, preserving the structure and bringing out the colors.  As one can see, comparing this one and the prior one, patterns are also changeable and totally agreeable to customizing. Write your name!